1. Field of the Invention
This application is related to integrated circuits and more particularly to data communications links between integrated circuits.
2. Description of the Related Art
System level characterization at pins of an integrated circuit in a data communications system operating at high frequency rates (e.g., 1.0 GHz or greater) may be difficult to measure and may not provide useful information with respect to signal characteristics at the integrated circuit pad. Therefore, it is difficult to quantify the operating margin of a particular data communications system. Probing signals at the integrated circuit pad may be impracticable in some systems and in other systems may not provide information regarding the response of an input amplifier to complex voltage waveforms delivered by a channel. Although it may be possible to measure global voltage margin and global frequency margin of the system, such techniques do not provide direct information about electrical parameters of a specific communications link, e.g., time margin at the receiver of a sampling device. Accordingly, improved techniques for characterizing and testing a communications link are desired.